Method of addressing film liftoff in mems fabrication

Abstract

A method of fabricating a MEMS device. A first spacer is formed above a CMOS substrate containing circuitry. Vias are formed within the first spacer. A first metal is formed above the first spacer and vias and patterned to form a MEMS element. A second spacer is formed above the MEMS element and first spacer. A via is formed within the second spacer. A second metal is formed above the second spacer and the via. A capping layer is formed above the second metal. The second metal is patterned to form a second MEMS element. The device is cleaned using a developer solution while the capping layer protects the second MEMS element. The first and second spacers are removed to release the first and second MEMS elements.

1 . A method of fabricating a digital micromirror device, the method comprising:
 forming a first spacer above a CMOS substrate containing circuitry;   forming hinge vias within the first spacer;   depositing a first metal above the first spacer and hinge vias and patterning the first metal to form a hinge;   forming a second spacer above the hinge and first spacer;   forming a mirror via within the second spacer;   depositing a second metal above the second spacer and the mirror via;   forming a sacrificial dielectric capping layer on a surface of the second metal;   patterning the second metal to form a mirror;   cleaning the device using a developer solution; and   removing the first and second spacer layers to release the hinge and mirror.   
     
     
         2 . A method of fabricating a digital micromirror device, the method comprising:
 forming a first spacer above a CMOS substrate containing circuitry and patterning the first spacer to form openings for the hinge vias;   depositing a hinge liner metal above the first spacer and hinge vias to form a hinge via liner;   depositing a hinge via plug material above the hinge via liner to form a hinge via plug;   removing hinge via liner metal and hinge via plug material from above the first spacer;   depositing a hinge metal above the first spacer and hinge vias and patterning the hinge metal to form a hinge;   forming a second spacer above the hinge and first spacer and patterning the second spacer to form a mirror via;   depositing a mirror metal above the second spacer and mirror;   depositing an anti-reflective layer within a central indentation in the mirror via;   forming a sacrificial dielectric capping layer on a surface of the mirror metal;   depositing, patterning and exposing patterning layers above the capping layer;   etching the mirror metal to form a mirror;   cleaning the device using a developer solution;   removing patterning layers using a descum process; and   removing the first and second spacer layers to release the hinge and mirror.   
     
     
         3 . The method of  claim 2 , wherein the capping layer is deposited using chemical vapor deposition. 
     
     
         4 . The method of  claim 2 , wherein a thickness of the capping layer is 10 to 100 Angstroms. 
     
     
         5 . The method of  claim 2 , wherein the capping layer comprises an oxynitride. 
     
     
         6 . The method of  claim 2 , wherein the capping layer is deposited using sputtering. 
     
     
         7 . The method of  claim 2 , wherein at least a majority of the capping layer is removed using an ash process. 
     
     
         8 . The method of  claim 2 , wherein the capping layer comprises a metal oxide. 
     
     
         9 . The method of  claim 7 , wherein a portion of the capping layer is not removed from the mirror metal surface. 
     
     
         10 . A method of fabricating a microelectromechanical systems (MEMS) device, the method comprising:
 forming a first spacer above a CMOS substrate containing circuitry;   forming vias within the first spacer;   depositing a first metal above the first spacer and vias and patterning the first metal to form a first MEMS element;   forming a second spacer above the first MEMS element and first spacer;   forming a via within the second spacer;   depositing a second metal above the second spacer and the via;   forming a sacrificial dielectric capping layer on a surface of the second metal;   patterning the second metal to form a second MEMS element;   cleaning the device using a developer solution; and   removing the first and second spacer layers to release the first and second MEMS elements.   
     
     
         11 . The method of  claim 10 , wherein the capping layer is deposited using chemical vapor deposition. 
     
     
         12 . The method of  claim 10 , wherein the capping layer is deposited using sputtering. 
     
     
         13 . The method of  claim 10 , wherein a thickness of the capping layer is 10 to 100 Angstroms. 
     
     
         14 . The method of  claim 10 , wherein the capping layer comprises an oxynitride. 
     
     
         15 . (canceled). 
     
     
         16 . The method of  claim 10 , wherein at least a majority of the capping layer is removed using an ash process. 
     
     
         17 . The method of  claim 10 , wherein the capping layer comprises a metal oxide. 
     
     
         18 . The method of  claim 16 , wherein a portion of the capping layer is not removed from the second metal surface. 
     
     
         19 . The method of  claim 1 , wherein the capping layer is deposited using chemical vapor deposition. 
     
     
         20 . The method of  claim 1 , wherein the capping layer is deposited using sputtering. 
     
     
         21 . The method of  claim 1 , wherein a thickness of the capping layer is 10 to 100 Angstroms. 
     
     
         22 . The method of  claim 1 , wherein the capping layer comprises an oxynitride. 
     
     
         23 . The method of  claim 1 , wherein the capping layer comprises a metal oxide. 
     
     
         24 . The method of  claim 1 , wherein at least a majority of the capping layer is removed using an ash process. 
     
     
         25 . The method of  claim 8 , wherein a portion of the capping layer is not removed from the mirror metal surface.